WHEN THE SKIN SPEAKS SCLERODERMA BUT THE ANTIBODIES WHISPER LUPUS: A CASE REPORT

Abstract

Overlap syndrome is the coexistence of clinical features of more than one connective tissue disease in a singlepatient, often accompanied by a mixed serological profile. Systemic sclerosis with overlapping lupus serology maypresent predominantly with scleroderma manifestations while fulfilling immunological criteria for systemic lupuserythematosus. We report the case of a 40-year-old woman who presented with progressively worsening dyspnea over7 years, skintightening, dysphagia, non-productive cough, and winter-predominant painful bluish discoloration of thefingers. Examination revealed tight skin with a modified Rodnan skin score of 21/51, Raynaud’s with digital gangrene,raised jugular venous pressure, and bilateral inspiratory crepitations. Investigations showed type 1 respiratory failure,anemia, leukocytosis, and basal reticular opacities on imaging. High-resolution computed tomography of the chestrevealed a non-specific interstitial pneumonia (NSIP) pattern of interstitial lung disease (ILD). Serological analysisdemonstrated a positive antinuclear antibody with a homogeneous pattern and positive anti-double-stranded DNA,smD1, and nucleosome on immunoblot. Nailfold capillaroscopy showed dilated loops and avascular areas, consistentwith secondary Raynaud’s phenomenon. Pulmonary function test was suggestive of moderate restriction. A diagnosisof scleroderma-dominant overlap syndrome with secondary Raynaud’s phenomenon and NSIP-pattern interstitiallung disease was established. The patient was managed with low-dose corticosteroids, hydroxychloroquine, tadalafil,bosentan, mycophenolate mofetil, and rituximab, with clinical improvement observed on follow-up